Biosorbents are materials with capability to adsorb pollutants from wastewater solutions offering a promising solution for environmental remediation. Among these materials, sodium alginate (SA) is a naturally occurring biodegradable polysaccharide derived from brown seaweed. SA has gained significant attention due to its hydrophilic ability, cost-effectivity as well as versatility. With the evolution in industries an ever-increasing concern regarding the wastewater treatment of industrial effluents, which contain combination of contaminants like heavy metals, oils, and dyes, raises an urgent need for effective and sustainable water treatment methods. Despite the utility, the conventional methods are limited in their efficacy and scalability highlighting the critical demand for innovative approaches. This chapter focuses on the development and application of alginate-based biosorbents specifically designed to address the limitations of traditional water treatment methods through modifying sodium alginate through techniques like cross-linking with nanoparticles and combining with biopolymers to form bio-composites—these novel biosorbents exhibit enhanced adsorption capacity and stability along with antibacterial properties. The chapter delves into various formulations and their effectiveness in eliminating a wide range of contaminants from aqueous solutions by showcasing structural and functional advantages of alginate-based solutions focusing on both a viable alternative for effective wastewater treatment along with its emphasis on environmental and economical benefits associated with utilizing biodegradable materials addressing the growing challenge of water pollution.